Congenital megalourethra: prenatal diagnosis and postnatal/autopsy findings in 10 cases

Congenital megalourethra

Background

Congenital megalourethra is a urogenital anomaly characterized by a cystic dilatation and elongation of the penile urethra resulting from the absence and hypoplasia of the corpus spongiosum and corpus cavernosum, or anterior urethral valve. There are two clinical types: scaphoid and fusiform. Generally, the etiology is unknown, but it is thought to be a defect in mesodermal development. Fewer than 100 cases have been reported in the literature, and the exact incidence is unclear. In most cases, the surgical procedure is challenging and requires extensive reconstructive and/or replacement surgery.

Case presentation

We present a 6-month-old boy suffering from a cystic dilatation of the penile urethra along with urine dribbling during micturition since birth. The patient was diagnosed with the scaphoid type of megalourethra and was operated on using reduction urethroplasty. On the 21st post-operative day, we removed the Foley catheter and followed the patient on two occasions (the 45th post-operative day and the 6th post-operative month) with excellent results.

Conclusion

The anagement of megalourethra depends on the clinical type. Meticulous surgical technique, the use of fine suture materials with careful handling, and fixation of the vascularized flap are the main principles of an acceptable result. Observation of erectile function and fertility require long-term follow-up.

Fetoscopic urethral meatotomy in fetuses with lower urinary tract obstruction by congenital megalourethra

BACKGROUND

To describe the perinatal outcomes of fetoscopic urethral meatotomy (FUM) in fetuses with lower urinary tract obstruction (LUTO) by congenital megalourethra.

STUDY DESIGN

Between 2012 and 2020, 226 cases with LUTO were referred to our fetal surgery center in Queretaro, Mexico. We report the perinatal outcome of cases with LUTO by congenital megalourethra that were selected for FUM in an attempt to release the penile urethral obstruction.

RESULTS

Congenital megalourethra was diagnosed in 10 cases (4.4%) but only 3 cases (30%) with obstructive megalourethra and megacystis were selected for fetal surgery. Fetoscopic urethral metatotomy was successfully performed in all three cases at a median gestational age (GA) of 21.4 (18.0-26.7) weeks and with a median surgical time of 27 (12-43) min. A resolution of urethral dilatation and subsequent reduction of the penile length and normalization of both the bladder size and amniotic fluid were observed in all cases. The median GA at delivery was 35.2 (range: 30.6-38.0) weeks. There were no fetal deaths but one neonatal death (33%) secondary to renal failure and preterm delivery.

CONCLUSION

In fetuses with LUTO by congenital obstructive megalourethra, FUM is feasible and is associated with good perinatal outcomes.

Prenatal diagnosis of congenital megalourethra in the second trimester of pregnancy

Congenital megalourethra is abnormal dilation of the penile urethra due to aplasia of erectile tissue, leading to lower urinary tract obstruction. This condition should be considered when fetal penis with typical dilation is seen on prenatal scan. The dilated structure, however, can be easily missed or misinterpreted as the umbilical cord. Perinatal prognosis is poor due to direct consequences on urinary and respiratory systems, or due to severe associated anomalies. A large number of survived cases experience urinary sequelae and renal impairment. We report one case of fetal congenital megalourethra diagnosed at 17 weeks and 6 days of pregnancy.

Prenatal diagnosis and postnatal outcome of anterior urethral anomalies

OBJECTIVES

Anterior urethral anomalies (AUA) which present as anterior urethral valve, stenosis or atresia, are a rare cause for congenital urinary tract obstruction. We present our AUA prenatal diagnosis case series.

METHODS

Fetuses presenting with prenatal findings suggestive for AUA according to postnatal reported clinical and imaging signs (urinary tract dilatation, dilated bladder, enlarged edematous fetal penis, dilatation of the fetal urethra and diverticula) were followed prospectively.

RESULTS

Six fetuses were diagnosed with AUA. Diagnosis was confirmed upon examination of the neonate or the abortus. All cases presented with variable degrees of urinary tract dilatation. Four fetuses who presented with additional congenital anomalies of the kidneys and urinary tract (CAKUT) developed intra-uterine or early postnatal renal failure, while two isolated AUA cases have a normal renal outcome.

CONCLUSIONS

AUA is a rare diagnosis. However, high index of suspicion and careful sonographic assessment of the male fetal urethra in cases referred for urinary tract dilatation may enable appropriate parent counseling, optimal prenatal surveillance and timed postnatal urological intervention. As in other lower urinary tract obstructions, future renal function seems to correlate with associated CAKUT, therefore close follow up throughout pregnancy and meticulous sonographic assessment is recommended.

Prenatal diagnosis of congenital megalourethra with imperforate anus

Background

Congenital megalourethra is a rare prenatal finding while prenatal diagnosis of imperforate anus poses high challenge. This is the first prenatally ultrasound diagnosed case which had congenital megalourethra and imperforate anus. This case demonstrated the possibility of using the prenatal imaging findings to evaluate the postnatal prognostic outcomes in multi-organ anomalies.

Case

We present a case of congenital megalourethra, diagnosed prenatally at 22 weeks’ gestation, in which the penis appeared severe dilated with complete absence of the corpora spongiosa and cavernosa. This case also revealed absence of perianal muscle which was in associated with imperforate anus. Detailed prenatal ultrasonographic findings predicted the high possibility of poor outcome of the fetus in the pulmonary, renal, and sexual functions.

Conclusion

This case serves to identify not only the marked bilateral hydronephrosis features but also the striking lower urethral malformation with obstruction flow effect of the penis. Indeed we believe this is the first case report of a rare case of fetal megalourethra associated with imperforate anus at early second trimester on ultrasonography imaging.

Long-term renal outcome in infants with congenital lower urinary tract obstruction

INTRODUCTION

Congenital Lower Urinary Tract Obstructions (LUTO) is a heterogeneous group of diseases in which urine elimination is obstructed at the level of bladder neck or urethra. The aim of the study is to evaluate the long-term renal outcome of patients suffering of congenital LUTO.

PATIENTS AND METHOD

We retrospectively reviewed patients with congenital LUTO. All patients had at least 1 year follow-up. Data on surgery, renal imaging and Schwartz estimate creatinine clearance were collected. Incidence of Chronic Renal Disease (CRD) is presented with Kaplan-Meier method.

RESULTS

40 patients were included, 23 patients with Posterior Urethral Valve (PUVs) and 17 patients with other aetiologies: anterior urethral valve (2), urethral atresia (2), urethral stenosis (2), cloacal malformations (2), obstructive ureterocele (1), bladder trigone malformation (1) and neonatal bladder-sphincter dysfunction without neurological abnormalities (7). Incidence of CRD at age 10 years was 37% in congenital LUTO, 42% in PUVs and 30% in other aetiologies, and was significantly higher in PUVs (P=0.032). Renal prognosis was significantly worsened by discover of retentional bladder wall changes in initial cystoscopy, and by loss of parenchymal differentiation or cortical microcysts in first ultrasonography. The use of urinary diversion was significantly higher in LUTO of other aetiologies.

CONCLUSION

A high incidence of CRD is observed in patients with congenital LUTO, significantly higher in patients with PUV. LUTO of other aetiologies require step by step surgical management and higher use of urinary diversion. Precise initial evaluation in cystoscopy and ultrasonography is required and participate to evaluate future renal outcome.

LEVEL OF INCIDENCE

4.

Congenital anterior urethrocutaneous fistula at the penoscrotal junction with proximal penile megalourethra: A case report

Congenital anterior urethrocutaneous fistula and megalourethra are both rare anomalies. These anomalies are commonly associated with other anorectal or genitourinary anomalies and evaluated with voiding cystourethrography. We examined a 34-month-old boy who presented with a fistula at the penoscrotal junction. A voiding cystourethrogram showed a jet of urine coming through the fistula and proximal saccular dilatation of the penile urethra. We present the imaging findings of the first case of an association between a congenital anterior urethrocutaneous fistula at the penoscrotal junction and a proximal penile megalourethra. We also discuss the etiology, management, and differential diagnosis of this entity, and review the literature.

Prenatal Diagnosis and Perinatal Outcomes of Congenital Megalourethra: A Multicenter Cohort Study and Systematic Review of the Literature

OBJECTIVES

The purpose of this study was to evaluate the prenatal findings and postnatal outcomes in fetuses with congenital megalourethra.

METHODS

This retrospective study reviewed our experience and the literature between 1989 and 2014. Prenatal findings were evaluated and compared with postnatal findings, including neonatal mortality and abnormal renal function (need for dialysis or renal transplantation).

RESULTS

Fifty fetuses with congenital megalourethra were analyzed, including 6 cases diagnosed in our centers. Most cases (n = 43 [86.0%]) were diagnosed in the second trimester. Only 1 case was diagnosed in the first trimester, whereas 6 cases (12.0%) were diagnosed in the third trimester. Thirty-five fetuses (70.0%) survived. Bilateral hydroureters were associated with perinatal death (P= .024). Among the survivors, 41.9% of the neonates had renal impairment. The following factors were associated with postnatal renal impairment: presence of severe oligohydramnios/anhydramnios (P = .033), bilateral hydronephrosis (P = .008), and earlier gestational age at delivery (P = .022).

CONCLUSIONS

In fetal megalourethra, bilateral hydroureters, bilateral hydronephrosis, and severe oligohydramnios/anhydramnios are associated with neonatal mortality and renal impairment.

Successful Fetoscopic Surgery to Release a Complete Obstruction of the Urethral Meatus in a Case of Congenital Megalourethra

We report the successful use of fetoscopy to treat a case of severe low urinary tract obstruction (LUTO) secondary to a congenital megalourethra. A second trimester male fetus presented at 21 weeks of gestation with massive dilatation of the penile urethra. In addition, bilateral hydronephrosis, an enlarged and hypertrophic bladder, with progressive oligohydramnios were found, suggesting poor prognosis. Extensive counselling was performed and, after the approval from the local ethics committee and informed consent, patients accepted fetal therapy by fetoscopy. The procedure consisted in fetoscopic identification of the tip of the penis and confirmation of the complete absence of the urethral meatus. Thereafter, under combined endoscopic and ultrasound guidance a perforation of the tip of the penis was performed with contact diode laser, until an opening into the urethra was achieved. After the operation, resolution of the cystic penile dilation, with reduction of the penile size, and normalization of the amniotic fluid volume were observed. The pregnancy continued uneventfully and a normal male infant was born at term at the local hospital. The baby was developing normally with normal renal function at 6 months of age. Our report demonstrates that fetoscopic decompression of a distal urethra obstruction can achieve neonatal survival in the rare event of congenital megalourethra.

Lower urinary tract obstruction in the fetus and neonate

This article summarizes the most recent literature regarding congenital lower urinary tract obstruction in the fetus and newborn. Lower urinary tract obstruction is a heterogeneous group of rare diagnoses that have significant potential for in utero mortality and long-term morbidity in survivors. The diagnosis and management of the most common causes are reviewed. In addition, the current state of prenatal intervention for congenital lower urinary tract obstruction is discussed.

Lower urinary tract development and disease

Congenital anomalies of the lower urinary tract (CALUT) are a family of birth defects of the ureter, the bladder, and the urethra. CALUT includes ureteral anomaliesc such as congenital abnormalities of the ureteropelvic junction (UPJ) and ureterovesical junction (UVJ), and birth defects of the bladder and the urethra such as bladder-exstrophy-epispadias complex (BEEC), prune belly syndrome (PBS), and posterior urethral valves (PUVs). CALUT is one of the most common birth defects and is often associated with antenatal hydronephrosis, vesicoureteral reflux (VUR), urinary tract obstruction, urinary tract infections (UTI), chronic kidney disease, and renal failure in children. Here, we discuss the current genetic and molecular knowledge about lower urinary tract development and genetic basis of CALUT in both human and mouse models. We provide an overview of the developmental processes leading to the formation of the ureter, the bladder, and the urethra, and different genes and signaling pathways controlling these developmental processes. Human genetic disorders that affect the ureter, the bladder and the urethra and associated gene mutations are also presented. As we are entering the postgenomic era of personalized medicine, information in this article may provide useful interpretation for the genetic and genomic test results collected from patients with lower urinary tract birth defects. With evidence-based interpretations, clinicians may provide more effective personalized therapies to patients and genetic counseling for their families.

Megalourethra: a case report managed with a single intrauterine bladder aspiration

Congenital megalourethra is a rare mesenchymal anomaly of the male urethra, characterised by severe dilatation of the penile urethra due to congenital absence of the corpus spongiosum and/or corpus cavernosum. Postnatal complications include voiding and erectile dysfunction as well as renal insufficiency and pulmonary hypoplasia. We present a unique case of congenital megalourethra diagnosed prenatally in the early second trimester. The parents opted to continue pregnancy and vaginal delivery of a live neonate occurred with a favourable outcome.